Monteagudo Sánchez-Movellán, F. J.; Butler Sierra, I.; Bastida Milián, F. Ecology, Reproductive Biology and Conservation of Picris Willkommii (Schultz Bip.) Nyman (Asteraceae): An Endemic, Protected Species from Therophytic Grasslands of South-Western Iberian Peninsula. For. syst. 2009, 18, 28-41.